Verify we don't have any address phis

Author: meg-gupta

lib/SIL/Verifier/SILVerifier.cpp

@@ -1065,24 +1065,6 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
     return InstNumbers[a] < InstNumbers[b];
   }
 
-  // FIXME: For sanity, address-type phis should be prohibited at all SIL
-  // stages. However, the optimizer currently breaks the invariant in three
-  // places:
-  // 1. Normal Simplify CFG during conditional branch simplification
-  //    (sneaky jump threading).
-  // 2. Simplify CFG via Jump Threading.
-  // 3. Loop Rotation.
-  //
-  // BasicBlockCloner::canCloneInstruction and sinkAddressProjections is
-  // designed to avoid this issue, we just need to make sure all passes use it
-  // correctly.
-  //
-  // Minimally, we must prevent address-type phis as long as access markers are
-  // preserved. A goal is to preserve access markers in OSSA.
-  bool prohibitAddressPhis() {
-    return F.hasOwnership();
-  }
-
   void visitSILPhiArgument(SILPhiArgument *arg) {
     // Verify that the `isPhiArgument` property is sound:
     // - Phi arguments come from branches.
@@ -1106,7 +1088,7 @@ class SILVerifier : public SILVerifierBase<SILVerifier> {
                 "All phi argument inputs must be from branches.");
       }
     }
-    if (arg->isPhi() && prohibitAddressPhis()) {
+    if (arg->isPhi()) {
       // As a property of well-formed SIL, we disallow address-type
       // phis. Supporting them would prevent reliably reasoning about the
       // underlying storage of memory access. This reasoning is important for